Catenary cable link



Feb. 22, 1966 J. 5. BROWN CATENARY CABLE LINK PM June 26, 1964 INVENTOR. John S. Brown BY-' flan/1 United States Patent 3,235,927 CATENARY CABLE LINK John S. Brown, Framingham, Mass, assignor to the United States of America as represented by the Secretary of the Army Filed .l'une 26, 1964, Ser. No. 378,473 4 Claims. (Cl. 24-129) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein, if patented, may be manufactured and used by or for the government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a cable connecting device, and more particularly to a device for releasably connecting a cable at a point between its ends to a fixed anchor hook having a constricted throat opening.

Air-supported shelters are used by the Armed Forces for the protection of weapons and specialized equipment against the Weather. A big advantage inherent in this type of shelter is its lack of rigid supporting structures. However, such shelters are usually anchored to the ground or some other solid base by means of ground anchors and cables. Air-supported shelters are usually made of flexible fabric or film and are provided with a cable completely encircling the shelter and fastened to the base thereof by a series of fabric slings. The slings are spaced to expose portions of the cable at intervals of about two feet, so that the cable may be coupled to anchor hooks at these points. When the shelter is anchored at all such points along its base and inflated, the cable assumes a configuration suggestive of a series of catenaries; hence is usually referred to as a catenary cable.

Some of the air-supported shelters used by the Armed Forces are very large and are on occasion subjected to Windstorm-s which concentrate extremely large forces on the supporting anchor hooks and catenary cable. These forces quite often cause slippage of the catenary cable in the anchor hook, thus producing sawing or abrading action on the catenary cable by the anchor hook. As a result, the catenary cable becomes badly frayed at one point or another relatively quickly, necessitating frequent replacement thereof to avoid the possibility of its breaking under the high tensile stresses imposed by a windstorm.

Furthermore, it is customary to install the anchor hooks in wells or depressions in a hardstand foundation so that the anchor hooks will not interfere with the movement of vehicles or equipment over the hardstand surface when no shelter is mounted thereon. In winter this results in ice formation in the anchor hook wells, making it difficult to connect or disconnect the catenary cable and anchor hook.

It is, therefore, an object of the invention to provide an improved cable connecting device for releasably connecting a cable to an anchor hook.

Another object is to provide a coupling device for easily connecting and disconnecting a catenary cable of an airsupported shelter with respect to a fixed anchor hook whereby fraying of the catenary cable will be substantially prevented.

Another object is to provide a coupling device which can be easily removed from a fixed anchor hook without the use of tools.

A still further object is to provide such a device which will be simple and inexpensive to manufacture.

In the accompanying drawing, wherein one embodiment of the invention is shown:

FIGURE 1 is a front elevation of the cable connecting device in accordance with the present invention;

FIGURE 2 is a wide view in elevation of the cable connecting device;

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FIGURE 3 is a perspective view of an anchor hook mounted in an anchor well of a hard-stand for an airsupported shelter, a cable connecting device in accordance with the invention connected to the anchor hook, and a catenary cable connected to the cable connect-ing device, with portions of the catenary cable and the airsupported shelter broken away on both sides of the cable connecting device;

FIGURE 4 is a partial vertical section of a cable connecting device in accordance with this invention engaged in an anchor hook prior to rotation of the connecting device to permit its disengagement from the anchor hook; and

FIGURE 5 is a partial vertical section similar to FIG- URE 4 except that the connecting device has been totated to a position wherein it may be disengaged from the anchor hook.

In the illustrated embodiment of the invention, the cable connecting device is a unitary, strong, rigid, generally D-shaped ring-like member 10 formed of any suitable material, preferably metal, such as cast steel. The ring-like member may be considered as having four sides, a straight side 11, a curved side 12 opposite said straight side and tWo connecting sides 13, 14, extending between and connecting the ends of sides 11 and 12, all as shown in FIGURE 1. Curved side 12 engages a throa-ted anchor hook 15 mounted in a hardst-and 16, as best seen in FIGURE 3. The straight side 11 is preferably circular in cross section for a purpose to be described.

A tongue 17 is formed integrally with side 11 and extends inwardly of ring like member 10 a distance slightly greater than the diameter of the catenary cable 18 to permit the cable to be looped therearound as shown in FIG- URE 3. Tongue 17 is generally T-shaped having an integral cross member 19 formed at its inner end. Curved shoulders 20 and 21 are provided where the tongue 17 joins side 11 such that a catenary cable 18 looped around tongue 17 and contacting curved shoulders 20 and 21 is subjected to a snubbing action when the cable connecting device is in use. Projections 22 and 23 forming cross member 19 in the free end of tongue 17 prevent the catenary cable from slipping off the free end of the tongue when the cable is not under tension, such as during the early stages of inflation of an air-supported shelter. The tongue 17 is positioned so that the cross member 19 lies in a plane which is generally perpendicular to the plane in which the several sides of the ring-like member 10 lie, as best seen in FIGURE 2.

The cross-sectional diameter or thickness of side 12 is slightly greater than the size of the opening or throat 24 of the anchor hook 15 such that side 12 of the connecting device, although freely receivable in the bight 25 of the anchor hook, cannot pass through the throat 24 thereof under any conditions. Side 12 is preferably circular in cross section and formed lengthwise in a slightly curved shape as shown in FIGURE 1, permitting the connecting device to rock while engaged in the bight 25 of the anchor hook as the direction of pull on the catenary cable shifts during use.

The approximate central portions 26 and 27 of sides 13 and 14, respectively, are formed or flattened as best seen in FIGURES 1 and 5. These portions may be formed during the casting or molding of the cable connecting device or they may be formed by subsequent forging or machining. Portions 26 and 27 are formed to a thickness or diameter and width to freely pass through the throat 24 of the anchor hook 15 in either direction to either engage the cable connecting device in the anchor hook or to disengage it therefrom when desired.

In the use of the present invention, when it is desired to connect the catenary cable of an air-supported shelter to a number of anchor hooks mounted in a hardstand by means of the device of this invention, the cable connecting device is turned so that either flattened portion 26 of side 13 or flattened portion 27 of side 14 is passed through the throat 24 of the anchor hook. When side 13 or side 14 is within the bight 25 of the hook, the cable connecting device is rotated to the right or left, as the case may be, until side 12 is encompassed within bight 25. Since the diameter of side 12 is greater than the width of throat 24, ring cannot become disengaged from anchor hook 15, regardless of whether ring 10 is permitted to rotate about the longitudinal axis of side 12 in a manner such that side 11 is in front of or behind anchor hook 15. Consequently, when catenary cable 18 is disengaged from the cable connecting device, the latter will drop down into anchor well 28 in hardstand 16, permitting vehicles to pass freely along the surface of the hardstand without danger of breaking the shelter anchoring devices or damaging the tires of such vehicles. When the catenary cable 18 of an air-supported shelter, shown partly broken away at 29, is being connected to the cable connecting device, the shelter is usually deflated and the catenary cable is under little or no tension. An exposed section of the catenary cable 18 is pinched between the finders and thumb of one hand to form a loop which will pass through the opening between the cross member 19 and the top of anchor. hook 15. The cable connecting device is raised with the other hand and the loop of the catenary cable is inserted in the opening therein as indicated above and passed over the projection on the opopsite side of tongue 17 from the. side from which the loop was inserted in the opening. The loop in the cable is then released and as the cable straightens, it is drawn against curved shoulders 20 and 21 and the curved exterior surface of side 11. This operation is repeated at each anchor hook around the periphery of the air-supported shelter. When the catenary cable has been connected by way of cable connecting devices in accordance with this invention to anchor hooks at all points designed for attachment thereto, the shelter is closed and inflated, increasing tension on the cable 18 and increasing the snubbing effect of the connecting device on the cable as it is more tightly drawn against shoulders 20 and 21 and the curved surface of side 11.

Although the embodiment of the invention described above is for use with a throated type anchor hook, it is to be understood that the anchor hook and cable connecting device can be permanently joined to each other by closure of the hook around the cable connecting device, similarly to an eyebolt, thus preventing disconnecting of the cable connecting device while still permitting the cable connecting device to pivot within the opening of what might be called an anchor eye. In such a modification, if any damage occurs to the cable connecting device, it is difficult and more expensive to repair the shelter anchoring device than if the anchor hook is of the open type. Consequently, the open type anchor hook as described above is preferable. However, a closed anchor eye may be used in special situations; and in such cases, it is unnecessary to reduce the diameter of the sides 13 and 14 as at portions 26 and 27 since connection and disconnection will not be required.

While the cable connecting device has been illustrated in the form of a metal ring, it is to be understood that reinforced plastic or other strong, rigid materials may be used in making the cable connecting device.

The illustrated cable coupling device substantially reduces abrasion damage to the catenary cables of airsupported shelters by substantially eliminating the sawing action on the catenary cable caused by high winds acting on the shelter. The catenary cable is held tightly snubbed by the cable connecting device and any motion transmitted through the catenary cable is taken up by the shifting of the cable connecting device within. the

bight of the anchor hook. Both the anchor hook and the cable connecting device are made of relatively strong metal or other strong material which will withstand a great deal of abrasion without breaking; and even after prolonged usage, they can be readily replaced at relatively low cost in comparison with the cost of replacing the catenary cable.

It will be understood that various changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the invention, may .be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. A device for releasably connecting a cable at a point between its ends to a fixed anchor hook having a constricted throat comprising a closed ring-like member having a tongue extending inwardly thereof from a point on the inside surface of said member, said tongue having a projection on the free end thereof and being capable of engaging a loop of said cable between said projection and the inside surface of said ring-like member, a first portion of said ring-like member lying opposite said tongue being adapted for engagement in the bight of said anchor hook and having a minimum thickness greater than the throat of said anchor hook, said ring-like member having at least one other portion spaced from said first portion, said other portion having a thickness less than said first portion and being adapted to pass through thethroat of said anchor hook whereby said ring-like member may be releasably engaged in said anchor hook.

2. A device for releasably connecting a cable at a point between its ends to a fixed anchor hook having a constricted throat comprising a generally D-shaped ring member capable of engaging said anchor hook, said ring member having a generally T-shaped portion extending inwardly thereof from the approximate midpoint of the straight side of said ring member, said T-shaped portion being capable of engaging a portion of said cable between the cross member thereof and the straight side of said ring member, the portion of said ring member lying opposite the said straight side thereof being spaced from said T-shaped portion and having a generally circular cross section of a diameter larger than the throat of said hook, said ring member having at least one other portion thereof of reduced thickness and adapted to pass through the throat of said anchor hook whereby said ring member may be releasably engaged in said anchor hook.

3. A device for releasably connecting a cable at a point between its ends to a fixed anchor hook having a constricted throat comprising a closed ring-like member having a tongue extending inwardly thereof from a point on the inside surface of said member, the free end of said tongue being spaced from the opposite side of said ring-like member, said tongue having a projection on the free end thereof and being capable of engaging a loop of said cable between said projection and the inside surface of said member, a first portion of said ring-like member lying opposite said tongue being adapted for engagement in the bight of the anchor hook and having a generally circular cross section of a diameter larger than the throat of said hook, said portion being curved along its longitudinal axis whereby said member is rockable in the bight of said hook in response to tension in said cable, a second portion of said ring-like member lying between said first portion and said tongue being partially flattened to a thickness less than the diameter of said first portion to-permit said second portion to pass through the throat of said anchor hook whereby said ring-like member may be releasably engaged in said anchor hook.

4. A device for releasably connecting a cable at a point between its ends to a fixed anchor hook having a constricted throat opening comprising a closed ring-like member of generally circular cross section having a longitudinally curved portion receivable in the bight of said anchor hook and freely rockable relative thereto, said longitudinally curved portion having a diameter greater than the throat opening of said anchor hook, a tongue extending inwardly of said ring-like member from the inside surface of the portion of said ring-like member lying opposite said longitudinally curved portion, said tongue terminating at a point within the area defined by said ring-like member and spaced from said longitudinally curved portion thereof, said tongue having cable-retaining projections on the free end thereof and forming cable snubbing surfaces in conjunction with the portion of said ring-like member to which it is joined, said ring-like member having a partially flattened portion capable of passing through said throat opening of said anchor hook, said partially flattened portion lying between said longitudinally curved portion and said portion to which said tongue is joined, whereby said ring-like member may be rocked to position said partially flattened portion to pass through said throat opening for engaging and disengaging said ring-like member in said anchor hook.

References Cited by the Examiner UNITED STATES PATENTS References Cited by the Applicant UNITED STATES PATENTS 2,962,998 12/1960 Long.

WILLIAM FELDMAN, Primary Examiner.

BERNARD A. GELAK, Examiner. 

1. A DEVICE FOR RELEASABLY CONNECTING A CABLE AT A POINT BETWEEN ITS ENDS TO A FIXED ANCHOR HOOK HAVING A CONSTRICTED THROAT COMPRISING A CLOSED RING-LIKE MEMBER HAVING A TONGUE EXTENDING INWARDLY THEREOF FROM A POINT ON THE INSIDE SURFACE OF SAID MEMBER, SAID TONGUE HAVING A PROJECTION ON THE FREE END THEREOF AND BEING CAPABLE OF ENGAGING A LOOP OF SAID CABLE BETWEEN SAID PROJECTION AND THE INSIDE SURFACE OF SAID RING-LIKE MEMBER, A FIRST PORTION OF SAID RING-LIKE MEMBER LYING OPPOSITE SAID TONGUE BEING ADAPTED FOR ENGAGEMENT IN THE BIGHT OF SAID ANCHOR HOOK AND HAVING A MINIMUM THICKNESS GREATER THAN THE THROAT OF SAID ANCHOR HOOK, SAID RING-LIKE MEM- 